This proposal involves continuation of a new type of laser-based glaucoma surgery, transpupillary or corneal (T) argon (A) laser (L) coagulation (C) of the ciliary processes (TALC-I) which is low-risk and more effective than currently employed equivalent procedures. In addition, modification of the procedure and pilot clinical studies on the transcorneal laser photocoagulation of the chamber angle neovascularization and pilot laboratory studies on the 'under scleral flap' (TALC-II) procedures will be carried out. Efficacy of the TALC-I and TALC-II will be further investigated in the monkey eyes with argon laser-induced glaucoma. The research plan calls for: (1) producing glaucoma in normal monkey eyes with repeat circumferential argon laser photocoagulation of trabecular meshwork; (2) refining existing prototype instrumentation for clinical as well as laboratory application; (3) evaluating short- and long-term results of the procedures' effects upon aqueous humor dynamics first in monkeys, then in selected patients with uncontrollable aphakic and neovascular glaucoma; (4) defining clinical indications for the procedure; (5) continuing ongoing pilot studies on the TALC-II goniophotocoagulation in the treatment of neovascular glaucoma for comparison; and (6) initiating a laboratory study on TALC-II 'under scleral flap' photocoagulation. We estimate that the laser procedure will ultimately permit routine prevention or delay of blindness in patients with uncontrollable neovascular, hemorrhagic or aphakic glaucoma. It is our firm belief and hope that a useful clinical modality can be developed as an alternative procedure in preventing or delaying a devastating form of glaucoma.